WO2018228856A1 - Dispositif de freinage hydraulique renforcé - Google Patents

Dispositif de freinage hydraulique renforcé Download PDF

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Publication number
WO2018228856A1
WO2018228856A1 PCT/EP2018/064702 EP2018064702W WO2018228856A1 WO 2018228856 A1 WO2018228856 A1 WO 2018228856A1 EP 2018064702 W EP2018064702 W EP 2018064702W WO 2018228856 A1 WO2018228856 A1 WO 2018228856A1
Authority
WO
WIPO (PCT)
Prior art keywords
piston
master cylinder
brake booster
plunger
sectional area
Prior art date
Application number
PCT/EP2018/064702
Other languages
English (en)
Inventor
Leonardo Cadeddu
Original Assignee
Vhit S. P. A .Societa Unipersonal
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vhit S. P. A .Societa Unipersonal filed Critical Vhit S. P. A .Societa Unipersonal
Priority to EP18730312.8A priority Critical patent/EP3638554B1/fr
Priority to US16/620,564 priority patent/US11951954B2/en
Publication of WO2018228856A1 publication Critical patent/WO2018228856A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
    • B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
    • B60T13/14—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid using accumulators or reservoirs fed by pumps
    • B60T13/142—Systems with master cylinder
    • B60T13/145—Master cylinder integrated or hydraulically coupled with booster
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
    • B60T11/10—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting by fluid means, e.g. hydraulic
    • B60T11/16—Master control, e.g. master cylinders
    • B60T11/165—Single master cylinders for pressurised systems

Definitions

  • the invention relates in general to a boosted hydraulic braking device and, more specifically, it relates to a boosted hydraulic braking device equipped with a pressure- balancing device for working machines, such as agricultural tractors, earth-moving machines and the like.
  • hydraulic braking systems comprising one or more master cylinder (s) having a pumping function and actuated by a pedal or corresponding pedals are known within the field of motor vehicles.
  • braking systems further comprise boosted hydraulic braking devices, also called brake boosters (or hydroboosters) , associated to the master cylinder or to each master cylinder and advantageously provided within the body of the master cylinder.
  • brake boosters also called hydroboosters
  • the braking systems described in the above-cited patent applications provide, in particular, for the presence of a control piston (also called spool) connected to a brake pedal.
  • the control piston is adapted to drive a brake booster allowing to exert a pressure onto a piston of the master cylinder so that this piston generates, within a chamber of the master cylinder, a control pressure adapted to act onto braking members of a vehicle.
  • the brake booster comprises a brake booster piston arranged between a first chamber and a second chamber and integral with a plunger adapted to slide on the control piston. Under rest conditions, the first and the second chambers are connected to each other so that the boosting pressure is identical on both sides of the brake booster piston.
  • the connection between the first chamber and the second chamber is interrupted and the second chamber is brought into modulated connection with a discharge chamber.
  • the pressure within the second chamber becomes reduced and the pressure difference (delta pressure) between the two chambers exerts onto the brake booster piston a thrust which adds to the thrust exerted by the pedal, thereby making the pedal move towards the chamber of the master cylinder, thus amplifying the force exerted onto the piston of the cylinder and, consequently, the pressure exiting the master cylinder and therefore making braking easier.
  • Brake boosters are characterized by a parameter called "boosting ratio" R ass , defined as the ratio between the boosting force F ass , i.e. the force generated by the boosting system, and the incoming force F ln , i.e. the force exerted by the brake pedal.
  • boosting ratio is a parameter called "boosting ratio" R ass , defined as the ratio between the boosting force F ass , i.e. the force generated by the boosting system, and the incoming force F ln , i.e. the force exerted by the brake pedal.
  • a M c is the effective cross-sectional area of the master cylinder piston exerting pressure while advancing within the chamber of the master cylinder and ⁇ 3 ⁇ ⁇ is the effective cross-sectional area of the control piston exerting pressure while advancing towards the master cylinder piston.
  • Brake boosters of the known type though optimally performing their function of boosting braking, have the problem that they cannot be easily and cost-effectively modified when a different boosting ratio is required. Indeed, in such brake boosters, changing the boosting ratio involves either modifying the master cylinder or replacing the control piston with another one having a different cross-sectional area and therefore replacing other components, especially the plunger sliding on the control piston. Both solutions mentioned above are difficult to implement and involve remarkable costs in order to be practiced .
  • the object of the present invention is to overcome the drawbacks and limitations of the prior art by providing a hydraulic braking system which can be easily and cost- effectively modified in order to vary the boosting ratio of its brake booster.
  • the hydraulic braking device comprises a master cylinder and a brake booster.
  • a piston of the brake booster defines a first and a second pressurized chambers of the brake booster, said chambers being associated to communication means arranged to establish, under rest conditions of the braking device, a communication between the first and the second pressurized chambers of the brake booster and to interrupt such communication during braking.
  • a piston of the master cylinder defines a chamber of the master cylinder, said chamber being arranged to contain a pressurized fluid and a control pressure transmitted to one or more vehicle brakes being generated in said chamber.
  • the piston of the master cylinder is associated to a control piston which is mounted so as to be tightly slidable in a plunger of the piston of the brake booster and is driven by actuating a brake pedal.
  • the control piston comprises a first end portion, distal relative to the brake pedal and having a certain cross-sectional area arranged to cooperate with a gasket so as to establish, during braking, a modulated communication between the first chamber of the brake booster and a discharge chamber of the master cylinder.
  • the braking device has an effective cross-sectional area which is adapted to counter-act a pressure existing in a region comprised between the piston of the master cylinder and the control piston and is different from the cross- sectional area of the first end portion of the control piston .
  • the braking system comprises a bushing fixedly connected to the first end portion of the control piston.
  • the bushing comprises an outer surface arranged to cooperate with a gasket associated with the plunger, so that the effective cross-sectional area counter-acting the pressure existing in the region comprised between the piston of the master cylinder and the control piston is the effective cross-sectional area of the bushing.
  • the control piston comprises a thrust portion.
  • Said thrust portion comprises an outer surface arranged to cooperate with a gasket associated with the plunger, so that the effective cross-sectional area counter-acting the pressure existing in the region comprised between the piston of the master cylinder and the control piston is the effective cross-sectional area of the thrust portion.
  • Said ratio indeed, depends on the effective cross-sectional area adapted to counter-act the pressure existing in the region comprised between the piston of the master cylinder and the control piston.
  • said area is the effective cross-sectional area of the bushing or of the thrust portion of the control piston, it is easy to modify the boosting ratio by simply replacing the bushing or the control piston, in addition to the corresponding gasket cooperating with the bushing or with the thrust portion, and any means that may connect said gasket with the plunger, for instance washers or bushings.
  • Fig. 1 shows a sectional view of a hydraulic braking device according to a first embodiment of the invention
  • Fig. 2 shows an enlarged view of a detail A of the hydraulic braking device of Figure 1 ;
  • Fig. 3 shows a view of a part of the hydraulic braking device according to a second embodiment of the invention
  • Fig. 4 shows a view of a part of a hydraulic braking device according to a third embodiment of the invention.
  • a hydraulic braking device 100 (braking device) according to a first embodiment of the invention is shown, being part of braking system of an agricultural vehicle or the like.
  • the general structure of the braking device corresponds to the one described in EP 1457400 and WO 2017/013595, to which reference is made for a detailed description of the structure itself as well as of the operation thereof.
  • the main components of the braking device 100 will be briefly illustrated by focusing on those necessary for understanding the present invention.
  • rear refers to the right side of the braking system 100 facing towards a brake pedal
  • front refers to the left side (brake side) .
  • the braking device 100 also called master cylinder- brake booster assembly, comprises a body 30 having an axial hole 31 with a longitudinal axis X, said body housing both the members of the master cylinder 40 and those of the brake booster 50 and being divided by a fixed disk 36 into a front bore 32 with reduced diameter, in which the piston 41 of the master cylinder 40 slides longitudinally, and a rear bore 33 which has a diameter larger than that of the front bore 32 and in which a piston 51 of the brake booster 50 slides longitudinally .
  • the piston 41 of the master cylinder 40 defines, in the front bore 32, a chamber 42 (chamber of the master cylinder) which is arranged to contain oil at a control pressure depending on the force applied to the piston 41 of the master cylinder 40 by means of a brake pedal (not shown) and communicates with one or more brakes (not shown) of the vehicle .
  • the piston 51 of the brake booster 50 is associated to a control piston 12 (also called spool) extending through the rear bore 33 of the axial hole 31.
  • the control piston 12 comprises a first (front) end portion 12a and a second (rear) end portion 12b connected to an actuating rod 14 which in turn is connected to the brake pedal.
  • Both end portions 12a, 12b of the control piston 12 preferably have a diameter larger than that of a middle portion 12c thereof, which has a reduced diameter; said middle portion 12c, having regions or steps 34a, 34b for connection to the end portions 12a, 12b with larger diameter, defines a gap 49 between the outer surface 60 of the control piston 12 and the inner surface 61 of a plunger 11 of the piston 51 of the brake booster 50.
  • the plunger 11 slides on the control piston 12 exerting a sealing action against the end portions 12a, 12b thereof.
  • the piston 51 of the brake booster 50 further defines, within the rear bore 33 of the axial hole 31, a first (front) pressurized chamber 52, and a second (rear) pressurized chamber 53 communicating with a pressurized oil tank (not shown) .
  • Passageways 54 and 55 are provided between the chambers 52 and 53 and the gap 49, respectively, said passageways passing through the plunger 11 and, under rest conditions of the device (as shown in Fig. 1), communicate the front chamber 52 with the rear chamber 53 through the gap 49.
  • the control piston 12 moving towards the front region, obstructs the passageway 55, thus isolating the front chamber 52 from the rear chamber 53.
  • This gasketing system includes, among others, a first gasket 10, for example an O-ring, associated to the inner surface 61 of the plunger 11 and adapted to cooperate with the front end portion 12a of the control piston 12, and a second gasket 44, for example a lip-type gasket, arranged between the plunger 11 and the piston 41 of the master cylinder 40.
  • a first gasket 10 for example an O-ring
  • a second gasket 44 for example a lip-type gasket
  • modulation area A m The cross-sectional area of the front end portion 12a of the control piston 12 with which the gasket 10 cooperates, is defined here below as modulation area A m , because the interaction between the front end portion 12a and the gasket 10 allows, in a known manner (see EP 1457400), the modulated communication between the front chamber 52 and the discharge chamber 43.
  • the braking system 100 comprises a bushing 15 fixedly connected, for example screwed, to the front end portion 12a, distal relative to the actuating rod 14, of the control piston 12.
  • the bushing 15 is associated, by means of a counter-acting member 45, for example a spring, to the piston 41 of the master cylinder 40.
  • the bushing 15 is associated to a support washer 19 against which an end of the spring 45 abuts .
  • the braking device 100 further comprises a gasket 16, for example an O-ring, associated to the inner surface 61 of the plunger 11 and adapted to cooperate with the bushing 15, more particularly with an outer surface 62 of the bushing 15, so as to isolate the region 47 interposed between the bushing 15 and the piston 41 of the master cylinder 40 from the discharge chamber 43.
  • a gasket 16 for example an O-ring
  • the gasket 16 is constrained between two washers 17a, 17b, of which the first washer 17a abuts against a shoulder 46 provided on the inner surface 61 of the plunger 11 and the second washer 17b abuts against a Seeger ring 18 associated with the inner surface 61 of the plunger 11.
  • the effective cross-sectional area of the bushing 15, i.e. the cross-sectional area enclosed by the gasket 16, is the area that counter-acts the pressure that is gradually building up, in a known manner, in the region 47 by means of the brake booster.
  • a second embodiment of the braking device 200 according to the invention will be described below .
  • the braking device 200 is substantially identical to the one of the first embodiment and is shown in Fig. 3 only for the part containing elements differing from the first embodiment, whereas the same reference numerals used for the first embodiment are maintained for those elements that remain unchanged.
  • the braking device 200 comprises a control piston 212 in which a front end portion 212a, with which the gasket 10 cooperates, is followed by a thrust portion 215 associated, by means of a counter-acting member 45, for example a spring, with the piston 41 of the master cylinder 40. Therefore, unlike the first embodiment of the braking device 100, the braking device 200 does not comprise a bushing connected to its front end portion 212a.
  • the cross-sectional area of the front end portion 212a of the control piston 212 with which the gasket 10 cooperates is defined as modulation area A m , because the interaction between the front end portion 212a and the gasket 10 allows, in a known manner (see EP 1457400), the modulated communication between the front chamber 52 and the discharge chamber 43.
  • the braking device 200 further comprises a gasket 16, for example an O-ring, associated with the inner surface 61 of the plunger 11 and adapted to cooperate with the thrust portion 215, more particularly with an outer surface 262 of the thrust portion 215, so as to isolate the region 47 interposed between the thrust portion 215 and piston 41 of the master cylinder 40 from the discharge chamber 43.
  • a gasket 16 for example an O-ring
  • the gasket 16 is constrained between two washers 17a, 17b associated with the inner surface 61 of the plunger 11; for example, the first washer 17a abuts against a shoulder 46 provided on the inner surface 61 of the plunger 11 and the second washer 17b abuts against a Seeger ring 18 associated with the inner surface 61 of the plunger 11.
  • the effective cross-sectional area of the thrust portion 215, i.e. the cross-sectional area enclosed by the gasket 16, is the area that counter-acts the pressure that is gradually building up, in a known manner, in the region 47 by means of the brake booster.
  • control pistons 212 with different thrust portions 215, i.e. with different effective cross-sectional areas that differ from the modulation area A m defined above, it will be possible to easily vary the boosting ratio of the braking system 200, as will be better illustrated below.
  • a third embodiment of the braking device 300 according to the invention will be described below .
  • the braking device 300 is substantially identical to the one of the first embodiment; Fig. 4 shows only a part thereof and the same reference numerals used for the first embodiment are maintained for those elements that remain unchanged .
  • the gasket 16 is mounted in a ferrule 20 associated with the inner surface 61; for example, the ferrule 20 is tightly mounted, preferably with interference fit, between a shoulder 46 provided on the inner surface 61 of the plunger 11 and a Seeger ring 18 associated to the inner surface 61 of the plunger 11.
  • the effective cross-sectional area of the bushing 15, i.e. the cross-sectional area enclosed by the gasket 16, is the area that counter-acts the pressure that is gradually building up, in a known manner, in the region 47 by means of the brake booster.
  • the braking device 300 it is possible to use, advantageously, bushings of different size, i.e. with different effective cross- sectional areas, so as to easily vary the boosting ration, as will be better described below.
  • a further embodiment can also be provided, having a control piston comprising a thrust portion (and therefore having no bushing) , as described in the second embodiment, and means for retaining the gasket cooperating with the thrust portion, said retaining means being similar to those described in the third embodiment, i.e. including a ferrule instead of washers.
  • the ferrule 20 it is possible to use bushings 15 or control pistons with thrust portions 215 having effective cross-sectional areas that differ remarkably from the cross-sectional area delimited by the inner surface 61 of the plunger 11, because the ferrule 20 allows to easily compensate for such difference.
  • the braking device 100, 200 or 300 is the first braking device of a pair of braking devices (substantially identical to each other) of a braking system (not shown) of an agricultural vehicle or the like.
  • each braking device is associated with a corresponding brake of a rear wheel of the agricultural vehicle in order to be able to act onto a single rear brake and effect the so-called "steer-by-braking". It is therefore necessary to balance the control pressures provided by the master cylinders of the pair of braking devices in order to ensure balanced braking, i.e. a braking having substantially the same intensity on both rear wheels, when the pedals of both braking devices are actuated.
  • the braking devices are equipped with balancing devices.
  • the braking device 100, 200 or 300 includes a balancing device with a general structure, only briefly described below, corresponding to the one described in patent application WO 2017/013595, in the name of the Applicant, to which reference is made for a detailed description of the structure itself as well as of the operation thereof.
  • the balancing device 100, 200 or 300 comprises a stem 70 coaxial with the bushing 15 and/or the thrust portion 215 and fixed to the master cylinder 40, preferably at a front bottom 48 of the chamber 42 of the master cylinder 40.
  • the stem 70, coaxial with the control piston 12 or 212, comprises an inner surface, in which a balancing channel 71 is provided, and an outer surface.
  • the radial holes 73 are closed by a usually closed balancing valve, comprising, for example, a gasket 75, preferably fitted on a case 76 mounted, preferably with clearance, in the bushing 15 or in the thrust portion 215.
  • a usually closed balancing valve comprising, for example, a gasket 75, preferably fitted on a case 76 mounted, preferably with clearance, in the bushing 15 or in the thrust portion 215.
  • the balancing valve opens when the bushing 15 or the thrust portion 215, upon actuation of the brake pedal, and after overcoming the pre-load of the spring 45, moves towards the front portion of the master cylinder 40, so that the gasket 75, sliding along the stem 70, opens the radial holes 73, thus communicating the balancing channel 71 with a recess 77 provided within the bushing 15 or the thrust portion 215, and therefore with the chamber 42 of the master cylinder 40, through a region 47 provided between the piston 41 of the master cylinder 40 and the bushing 15 or the thrust portion 215, and through at least one radial hole 78 provided in the bushing 15 or in the thrust portion 215.
  • Balancing between the control pressures existing in the chambers of the master cylinders of the two braking devices is therefore actuated mechanically after a certain stroke of the corresponding control pistons, i.e. of the corresponding brake pedals.
  • the descried embodiments comprise a balancing device of the kind described, further embodiments may be envisaged having a different balancing device or no balancing device.
  • the bushing may be made, for instance, without the opening 74, adapted to receive the stem 70 of the balancing device, and without the corresponding gasket 75, without departing from the scope of the invention as defined in the appended claims.
  • the action of the brake booster 50 is triggered by the actuation of the brake pedal, upon which, as illustrated above, the front chamber 52 is isolated from the rear chamber 53 and is brought in modulated communication with the discharge chamber 43.
  • This causes a pressure drop in the front chamber 52 and therefore a pressure difference between the front chamber 52 and the rear chamber 53, said drop causing the piston 51 of the brake booster 50 to advance towards the front portion of braking device 100, 200 or 300.
  • the advancing of the piston 51 of the brake booster 50 causes in turn, by interacting with the gasket 44 in a known manner, establishment of a pressure in the region 47 interposed between the bushing 15 or the thrust portion 215 of the control piston 212 and the piston 41 of the master cylinder 40, said pressure causing advancing of the piston 41 of the master cylinder 40 and a pressure raise in the chamber 42 of the master cylinder 40, thus performing the brake boosting function.
  • the brake booster 50 according to the present invention is characterized by a boosting ratio R ass , defined as the ratio between the boosting force F ass , i.e. the force generated by the boosting system, and the incoming force, i.e. the force exerted by the brake pedal .
  • boosting ratio is:
  • p ass is the pressure existing within the front chamber 52
  • a ass is the area of the rear bore 33
  • a tUf f is the area of the plunger 11
  • p ou t is the pressure within the chamber 42 of the master cylinder 40 (control pressure)
  • a M c is the effective cross-sectional area of the piston of the master cylinder, i.e. the area of the front bore 32.
  • the first embodiment of the present invention it is possible to easily vary the boosting ratio by simply replacing the bushing 15 with another one having a different effective cross-sectional area and by replacing accordingly the O-ring 16, as well as the means (Seeger ring 18 and washers 17a, 17b or, alternatively, ferrule 20) fixing the gasket 16 to the plunger 11.
  • This indeed, makes it possible to vary the area A Spoo i without having to replace the whole control piston 12 and the plunger 11.
  • the second embodiment of the present invention it is possible to easily vary the boosting ratio by replacing the control piston 212 with another one having a thrust portion 215 with a different effective cross-sectional area and by replacing accordingly the O-ring 16, as well as the means (Seeger ring 18 and washers 17a, 17b or, alternatively, ferrule 20) fixing the gasket 16 to the plunger 11.
  • This makes it possible to vary the area ⁇ 3 ⁇ ⁇ while maintaining unchanged the size of the front end portion 212a (and consequently of the rear end portion) of the control piston 212 without having to replace the plunger 11.

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Braking Systems And Boosters (AREA)
  • Transmission Of Braking Force In Braking Systems (AREA)

Abstract

L'invention concerne un dispositif de freinage hydraulique comprenant un maître-cylindre et un servofrein. Le maître-cylindre comprend un piston de maître-cylindre (41) définissant une chambre de maître-cylindre qui est conçue pour contenir un fluide sous pression et dans laquelle une pression de commande est générée, qui est transmise à un ou plusieurs freins du véhicule. Le servofrein comprend un piston de servofrein (50) définissant une première et une seconde chambres sous pression du servofrein, lesdites chambres étant associées à des moyens de communication agencés pour établir, dans des conditions de repos du dispositif de freinage, une communication entre les première et seconde chambres sous pression du servofrein et pour interrompre une telle communication pendant le freinage. Le dispositif de freinage comprend un piston de commande (12) entraîné par actionnement d'une pédale de frein et monté de manière à pouvoir coulisser de manière serrée dans un plongeur (11) du piston du servofrein. Le piston de commande (12) comprend une première partie d'extrémité (12a) ayant une certaine zone de section transversale (Am) qui est agencée pour coopérer avec un joint d'étanchéité (10) de manière à établir, lors du freinage, une communication modulée entre la première chambre du servofrein et une chambre de décharge du maître-cylindre. Le dispositif de freinage présente une surface de section transversale effective (Α3ροοι) contrecarrant une pression existant dans une région (47) comprise entre le piston de maître-cylindre (41) et le piston de commande (12). Une telle zone (Α3ροοι) est différente de la zone de section transversale (Am) de la première partie d'extrémité (12a) du piston de commande (12).
PCT/EP2018/064702 2017-06-14 2018-06-05 Dispositif de freinage hydraulique renforcé WO2018228856A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP18730312.8A EP3638554B1 (fr) 2017-06-14 2018-06-05 Système de freinage hydraulique avec servofrein
US16/620,564 US11951954B2 (en) 2017-06-14 2018-06-05 Boosted hydraulic braking device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT102017000066182A IT201700066182A1 (it) 2017-06-14 2017-06-14 Dispositivo di frenatura idraulico servoassistito
IT102017000066182 2017-06-14

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Publication Number Publication Date
WO2018228856A1 true WO2018228856A1 (fr) 2018-12-20

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US (1) US11951954B2 (fr)
EP (1) EP3638554B1 (fr)
IT (1) IT201700066182A1 (fr)
WO (1) WO2018228856A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022069398A1 (fr) * 2020-10-02 2022-04-07 Vhit S. P. A. Societa Unipersonal Dispositif de freinage pour guidage autonome

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112810589B (zh) * 2021-01-07 2022-03-22 东风柳州汽车有限公司 制动主缸以及电动汽车

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2182407A (en) * 1985-10-31 1987-05-13 Teves Gmbh Alfred Vehicular anti skid hydraulic brake system
EP1457400A1 (fr) 2003-03-13 2004-09-15 VHIT S.p.A. Vacuum & Hydraulic Products Italy Dispostif hydraulique de freinage à sensibilité de freinage améliorée
EP1538047A2 (fr) * 2003-12-05 2005-06-08 Nissin Kogyo Co., Ltd. Système de freinage d'un véhicule
WO2009090078A2 (fr) * 2008-01-16 2009-07-23 Vhit S.P.A. Unipersonale Dispositif de freinage hydraulique ayant des mesures de sécurité, pour un tracteur agricole ou véhicule analogue
EP2105365A2 (fr) * 2008-03-28 2009-09-30 Nissin Kogyo Co., Ltd. Appareil de freinage véhiculaire
WO2017013595A1 (fr) 2015-07-21 2017-01-26 Vhit S.P.A. Soupape d'équilibrage à course commandée pour un système de freinage hydraulique, système de freinage comprenant le dispositif et procédé d'utilisation du système de freinage

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0038699B1 (fr) * 1980-04-23 1984-04-11 LUCAS INDUSTRIES public limited company Amplificateur commandé par force
IT1406552B1 (it) * 2010-09-16 2014-02-28 Vhit Spa Dispositivo idraulico di comando della frenatura in veicoli con doppio pedale di frenatura

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2182407A (en) * 1985-10-31 1987-05-13 Teves Gmbh Alfred Vehicular anti skid hydraulic brake system
EP1457400A1 (fr) 2003-03-13 2004-09-15 VHIT S.p.A. Vacuum & Hydraulic Products Italy Dispostif hydraulique de freinage à sensibilité de freinage améliorée
EP1538047A2 (fr) * 2003-12-05 2005-06-08 Nissin Kogyo Co., Ltd. Système de freinage d'un véhicule
WO2009090078A2 (fr) * 2008-01-16 2009-07-23 Vhit S.P.A. Unipersonale Dispositif de freinage hydraulique ayant des mesures de sécurité, pour un tracteur agricole ou véhicule analogue
EP2105365A2 (fr) * 2008-03-28 2009-09-30 Nissin Kogyo Co., Ltd. Appareil de freinage véhiculaire
WO2017013595A1 (fr) 2015-07-21 2017-01-26 Vhit S.P.A. Soupape d'équilibrage à course commandée pour un système de freinage hydraulique, système de freinage comprenant le dispositif et procédé d'utilisation du système de freinage

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022069398A1 (fr) * 2020-10-02 2022-04-07 Vhit S. P. A. Societa Unipersonal Dispositif de freinage pour guidage autonome

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EP3638554A1 (fr) 2020-04-22
IT201700066182A1 (it) 2018-12-14
US11951954B2 (en) 2024-04-09
US20200198608A1 (en) 2020-06-25
EP3638554B1 (fr) 2021-03-03

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